Introducing What is Injection Molding of Thermosetting Materials

Injection molding of thermosetting materials involves introducing the material into a thermosetting mold, where the screw rotates and is rapidly propelled forward using hydraulic pressure, forcing the thermosetting material into the mold. This rapid flow requires filling the mold cavity within 10 seconds, with pressure reaching approximately 190 MPa. Once the cavity is filled, the high-speed flow of the material generates significant frictional heat to accelerate the chemical reaction. After the cavity is filled, the injection pressure drops to a holding pressure of 30–70 MPa. This holding pressure is maintained on the material for about 8 seconds, after which the pressure is released, and the next cycle's plasticizing stage begins.

The thermosetting material remains in the thermosetting mold until it hardens, at which point the mold opens, and the product is ejected. The product may be slightly uncured and somewhat soft immediately upon ejection but completes curing within 2 to 3 minutes outside the mold due to the residual heat retained in the product. The entire production cycle of thermosetting products ranges from 30 to 180 seconds, depending mainly on the thickness of the product and the type of raw material used.